Introduction to Acids and Bases
Introduction to Acids and Bases
Acids
- An acid is a substance that releases hydrogen ions (H+) when dissolved in water. These ions are responsible for the characteristic properties of acids.
- Many acids can be found in household items. For instance, citric acid is in citrus fruits, and acetic acid gives vinegar its sour taste.
- Hydrochloric acid (HCl) is a common laboratory acid. It is one of the acids in your stomach and helps with digestion.
- Acids have a sour taste and corrosive property. Handle them with care as contact can cause burns.
Bases
- A base or alkali, is a substance that releases hydroxide ions (OH-) when dissolved in water.
- Bases are found in many cleaning products because they react with and neutralise fats and oils. Ammonia and baking soda are examples of basic substances.
- Sodium hydroxide (NaOH) is a strong base commonly used in labs. It’s used in manufacturing soap.
- Bases have a bitter taste and feel slippery to the touch. Like acids, they can cause burns if not handled safely.
Comparison of Acids and Bases
- Acids and bases are on opposite sides of the pH scale. Acids have a pH less than 7 and bases have a pH greater than 7.
- Acids turn blue litmus paper red whereas bases turn red litmus paper blue.
- Acids let off H+ ions in a solution and bases release OH- ions. The presence of these ions indicates the nature of the solution.
Neutralisation
- When you mix an acid and a base, they react in a process called a neutralisation reaction.
- This results in water and a type of salt being formed. The reaction removes the characteristic properties of acids and bases, bringing the pH closer to a neutral value of 7.
- For instance, when hydrochloric acid reacts with sodium hydroxide, salt and water are formed: HCl + NaOH -> NaCl + H2O.
Remember: Recognising basic and acidic substances around you, understanding the pH scale, and comprehending neutralisation reactions are crucial components of chemistry!